1. Technical Field
The present invention relates to a text messaging system for sending and receiving text messages among mobile terminals and information terminals connected via a network. More particularly, the present invention relates to a text messaging system for sending and receiving according to sender and receiver status text messages whose immediacy is strong, among multiple mobile terminals and information terminals connected to a computer network such as mobile a communication network or packet exchange network.
In the present invention, “packet exchange networks” mean networks for connecting personal computers (PC), workstations (WS), and PDAs (personal digital assistants); and the Internet, local area networks (LAN) and intranets can be cited as examples of packet exchange networks.
Mobile terminals are not particularly limited as long as they can send and receive text information via a mobile communication network, and mobile phones, personal handyphone systems (PHS), car phones, and pocket beepers can be cited as examples of mobile terminals. Information terminals are not particularly limited as long as they can send and receive text information via a network, and PCs, WSs, and PDAs can be cited as examples of information terminals.
2. Description of Related Art
FIG. 21 shows a conceptual structure of a conventional text messaging system using mobile phones, PHSs, and a center for relaying them.
A mobile terminal A sends wirelessly to a text message center text messages addressed to a mobile terminal B (1). The center comprehends condition of each mobile terminal with a detection part of radio condition. If the mobile terminal B is receivable, the text message center transmits the text message to the mobile terminal B. If the mobile terminal B is unreceivable because it is out of the radio area, for example, the text message center stores the text message in the storage area (2). At the moment that the mobile terminal B becomes receivable the text message center transmits the text message (3, 4, 5, 6, 7). A part of the mobile terminals B may connect to the center and obtain the text message stored in the center. Furthermore, text messages may be transmitted from mobile terminal A to mobile terminal B directly, not via the center. In this case, if the destination terminal is out of the radio area or on the phone, text messages are not received.
In the above-mentioned system in FIG. 21, a setting that e-mail is forwarded to a designated address is previously made. By storing in the center e-mail reached the designated address as a text message to a mobile terminal, e-mail is liaised with mobile terminals (9). There is also a system in which sender, title, and importance level of e-mail are previously set. When e-mail corresponding to forwarding conditions reaches the center, the e-mail is forwarded to a mobile terminal. Conversely, there is a system that when an e-mail address is inputted on the destination in a mobile terminal, the center transmits text messages as e-mail (8).
There already exists a system other than those above that an e-mail server detects e-mail arrival and notifies a predetermined mobile terminal of incoming of mail with information such as a sender of the e-mail, the title, and the time.
Meanwhile, as a means to detect other parties, statuses on a network, a monitor service of link state to the network, a busy condition management service of a service such as chat or electronic conference, an inventory management service, and a service computerized destination board are provided.
However, in a conventional text messaging system, text messages from mobile terminals are forwarded to e-mail only if such a setting is made. Receive messages cannot be received on a mobile terminal unless the setting once made is canceled. Furthermore, these setting and canceling are very troublesome. Receivers selectively use a send method of text messages such as e-mail and transfer to a mobile terminal regardless of the other party's status. On this account, selecting or switching a send mode according to the other party's status, which dynamically changes, is not performed.
For example, assume that a partner receiving text messages is connected to a network with a PC. In this case, receiving character messages on the PC instead of a mobile terminal is convenient for replying, enabling text messages to be immediately transmitted. Text messages of a mobile terminal are stored if the other party cannot receive them, but the sender cannot know that the messages are not immediately received. Under such circumstances, the sender cannot know if he/she needs to take another means or measure because the other party does not look at the sent text messages.
Since liaison of text message communication between mobile terminals and PCs are limited, it is difficult to freely transmit text messages to an information terminal currently used by the other party with a network application currently used by the other party. On this account, a user cannot communicate according to the other party's status and it is inconvenient for the user even if he/she know that the other party is connected to a network or network service in a place away from home.
Furthermore, an e-mail system can notify the sender a status that a sent e-mail did not reach the other party, for example. However, this system does not manage such dynamically-changing send result as the other party not having check the e-mail for certain time or the other party not having read it while he was using a network service.